"created" is not, imo, the right word here. Gates "harnessed" the effort of a paid workforce to accomplish a larger goal. The goal was to sell lots of software, which he successfully did with the help of his paid workforce.
Also IMO, "Rich Dad, Poor Dad" is an example of taking advantage of an existing system, it does not speak to whether or not the system is effective or justified, which I feel is the underlying frustration for OP. The fact that a man can effectively harness a workforce to accumulate wealth on a massive scale on his behalf (even after he no longer has any direct involvement) is possible in our current economic model. Economists (correct me if i'm wrong) generally consider this a "Good Thing" because it provides the encouragement to entrepreneurs and investors to try out new things and to invest in new markets. However, this is not the only way to encourage these behaviours. Co-operatives, partnerships and shared-ownership models all have similar benefits and the wealth generally spreads out more effectively. Why aren't these more popular forms of management in the US? That is largely down to the fact that the US has been under the control of "CEO" style economics for the better half of this century and those CEOs have used their power to sway government to craft their regulations and rules (Taxes especially!) in a manner that makes CEO style management more entrenched. IMO, the result of this economic evolution is one in which we now suffer from economic "monoculture". If you're going to be a business owner or an investor, you play this game because it's the only game in town. The result is massive accumulation of power, growing inequality and a lack of innovation in the way companies are managed and structured. --my two cents